NLAI BASE, Iraq -- The trainees opened withering fire on sandbagged positions and charged with guns blazing. Amid a howl of bloodcurdling cries one flopped to the ground, fired a grenade, then jumped up and sprayed an ememy bunker with submachinegun fire.

The attackers were women, soldiers of the National Liberation Army of Iran. At this NLAI training base on Iraqi soil, somewhere in the central sector of Gulf warfront, the bunkers were mock positions of Iranian government forces.

The women are part of a new army united by intense hatred for Ayatollah Ruhollah Khomeini and a deep desire to topple him.

Young men trained nearby with mortar launchers and Soviet-made Doushka antiaircraft guns recently captured from Khomeini's forces. Others drilled in hand-to-hand combat with short bayonets fixed to Czech-made Kalashnikov assault rifles. Some goose-stepped on parade in typical Iranian style.

Massoud Rajavi, one of Khomeini's most bitter foes, is commander in chief of the NLAI. He also heads the Mojahedin Khalq organization, which works underground inside Iran against the ayatollah. The NLAI is its military arm.

Rajavi set up the NLAI within a year after being expelled from France, when Prime Minister Jacques Chirac sought to mend relations with Tehran and got tough with Mojahedin exiles on French soil.

The NLAI fighters need no motivational pep talk. All volunteers, they work without pay.

Many suffered under Khomeini. Others have had brothers, sisters or fathers killed in Iran, either in street fighting or in prison, by execution or under torture.

'Death to Khomeini! Long live Rajavi!' shouted a woman fighter as she dropped a mortar into a launcher, put her fingers to her ears and swung around.

Women make up some 30 percent of the NLAI and go through the same training program as the men, said Soraya Shahri, commander of the women's unit on the base.

They take part in operations inside Iranian territory, she said. Television films made by the NLAI showed women fighting alongside men near Fakkeh, an Iranian border town opposite the Iraqi city of Amara.

'In the name of the martyrs of the Mojahedin Khalq, fire!' called Rajavi's wife Mariam, giving the attack order for the Fakkeh operation. The Mojahedin made a recording of her order.

Base commander Mehdi Barai said his troops have made several cross-border attacks during the past 10 months and were planning bigger ones.

'You will soon hear about them,' he told visiting newsmen.

In the March 28 attack at Fakkeh, several NLAI brigades swept into Iran with tanks and armored vehicles to maul the 77th Khorrassan Division, an elite force of the regular Iranian army.

Barai said his troops killed about 2,000 of Khomeini's troops, wounded another 1,500 and took 508 prisoners.

Unit commander Hossein Abrishamchi, using a pointer to show positions on a sand model, described a recent operation the central sector of the Iran-Iraq warfront.

'Our combatants attacked from the two ends (of the Iranian defense lines), here and here,' he said. 'They then swept around this way to the rear and captured all the positions of the regime's forces.'

Abrishamchi said his fighters found Khomeini's troops using 'dummy soldiers and dummy weapons' in several positions to multiply their real numbers.

In some places 'where we thought there were three or four machinegun nests, each manned by troops, we found one soldier manning all three or four, and running from one to the other to give the impression all were manned,' he said.

NLAI commanders displayed a large quantity of weapons captured from Iranian troops in the Fakkeh operation. These included four U.S.-made M-47 tanks, one armored personnel carrier and several jeeps.

'We had to leave 13 tanks behind,' an officer said. 'We destroyed them where we captured them.

'We have learned from our mistakes. Next time we'll bring back all the tanks we capture.'

Valued prizes were four night vision instruments. One mercury battery in the tripod-mounted instruments was dated March 15, 1983 and marked 'NATO No. 6135-99-114-44-1.'

The markings, and those of several other weapons captured, showed Khomeini's forces had acquired them only recently, perhaps during the Iran-Contra affair, an officer said.

'This is a classical army,' Abrishamchi said. 'We do have commando units, but we give our fighters training in classical warfare.'

Visiting journalists estimated the sprawling base accommodated about 5,000 soldiers. The NLAI said it has five large training bases of this sort along the war front, each with a string of smaller bases linked to it.

One estimate put the total number of NLAI troops at 25,000. Commanders refused comment on the figures, saying the army's strength is a military secret.

The force is made up mainly of Iranian exiles and deserters from the Iranian army, who infiltrate across the border, surrender to Iraqi troops and ask to be taken to an NLAI base. Not all are members of the Mojahedin Khalq.